APPLICATION OF ENZYMES IN TEXTILE INDUSTRY

Mr. Edward Menezes Director

Rossari Biotech201-A & B , Ackruti Corporate Park,

LBS Marg, Next to GE Gardens,Kanjurmarg (W)Mumbai 400 078.

Telephone nos + 91-22- 25777604/05Fax+91-22-25796982

E-mail: edward@rossarimail.com

The word Biotechnology is a cross between the Greek words

'bios' (everything to do with life) and 'techniques'

(involving human knowledge and skills). Biotechnology can

simply be defined as the application of living organism and

their components to industrial products and processes.

Biotechnology offers the potential for new industrial

processes that require less energy and are based on renewable

raw materials. Biotechnology makes use of biological systems

to manufacture products and provide services. The biological

systems that have traditionally been used are organisms such

as yeasts, fungi or bacteria. Thus, bio-tech can simply be

defined as the application of scientific and engineering

principles to the processing of materials by biological agents

to provide industrial products and processes, and an important

technology that will have a large impact on many different

industrial sectors in the future. It finds extensive

application in textiles and allied fields. The application of

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biotechnology to textile processing mainly consists of

application of enzymes to textile materials.

It is important to note that biotechnology is not just

concerned with biology, but it is a truly interdisciplinary

subject involving the integration of natural and engineering

sciences. Applications of biotechnology in textile wet

processing opens up a new horizon towards environmentally

friendly technology. Basic and applied research on microbial

cellulases, hemicellulases and pectinases has not only

generated significant scientific knowledge but has also

revealed their enormous potential in biotechnology.

Biotechnology has already lead to the development of new

products, opened new markets, speeded up production of pure

products and helped to reduce the pollution load. It also

offers the textile industry the ability

to reduce costs, protect the environment, addresses health and

safety and improve quality and functionality but the current

awareness of biotechnology is less. Therefore, the

applications are yet limited. Experience has shown that

whenever a clear economic justification and market for a

particular product or process exists, progress has been rapid.

So, it can be predicted that in the long term, more and more

of the cumbersome and polluting chemical procedures employed

by the textile industry will be substituted or supported by

the biotechnological processes.

Major applications of biotechnology in the textile industry

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Improvement of plant varieties used in the production

of textile fibres and in fibre properties.

Improvement of fibres derived from animals and health

care of the animals.

Novel fibres from biopolymers and genetically modified

micro-organisms

Replacement of harsh and energy demanding chemical

treatments by enzymes in textile processing

Environment friendly routes to textile auxiliaries

manufacturing such as dyestuffs

Novel uses of enzymes in textile finishing

Development of enzyme based detergents

New diagnostic tools for detection of adulteration and

Quality Control of textiles

Waste management

Following are the areas where biotechnology expected toplay an increasingly important role in the textile industryworldwide.

1. Fibres and Biopolymers Nature has provided us with textile fibres such as

Cotton, Wool, and Silk but there is now the potential to

harness biotechnology and produce new or modified fibres as

well as improve the production yields of existing fibres.

Cotton is still the world's leading textile fibre with some 20

million tons grown every year by about 80 producing countries.

However, cotton has the unfortunate characteristic of being

vulnerable to many insects, and to maintain yields, these

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insects are managed with large amounts of pesticides. Cotton

is also prone to infestation by weeds, which thrive under the

intense irrigation conditions that cotton needs throughout its

growth cycle, and cotton has poor tolerance to any of the

herbicides in use today. It is not surprising, therefore, that

biotechnology companies have focused their short-term

objectives on genetically engineering insect, disease, and

herbicide resistance into the cotton plant. Longer term goals

include the modification of fibre quality and properties (e.g.

length and strength) leading to the development of high

performance cottons.

In animal breeding and health care, biotechnology is

expected to have a large impact on animal fibre production

over the next few years. A whole range of new technologies are

now available including in vitro fertilisation and embryo

transfer, diagnostics, genetically engineered vaccines and

therapeutic drugs. Australia’s National Research Organisation

working on genetic modification of sheep to resist attack from

blowfly larvae by engineering a sheep that secretes an insect

repellent from its hair follicles and 'biological wool

shearing'. The latter technique relies on an artificial

epidermal growth factor which when injected into sheep

interrupts hair growth. A month later, breaks appear in the

wool fibre and the fleece can be pulled off whole in half the

time it takes to shear a sheep. There is also considerable

research being carried out in several countries with the aim

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of producing finer and therefore more valuable wool from

sheep.

Novel fibre-forming biopolymers are now being

manufactured using large-scale fermentation equipment. For

example, the bacterial storage compound polyhydroxybutyrate

(PHB) has been developed by Zeneca Bioproducts under the trade

name 'Biopol'. This high molecular weight linear polyester has

good thermoplastic properties (melting point 180°C) and can be

melt spun into fibres. Biocompatibility and biodegradability

makes PHB fibres ideally suited for surgical use; the body’s

enzymes slowly degrade sutures made from PHB. Zeneca is

currently using Biopol in conventional plastics applications

such as shampoo bottles.

Other biopolymers currently of particular interest in

wound-healing applications include the polysaccharides chitin,

alginate, dextran and hyaluronic acid. Chitin and its

derivative chitosan are important components of fungal cell

walls although these polymers are, at present manufactured

from seafood (shellfish) wastes. Patents by the Japanese

company Unitika cite the use of fibres made out of chitin in

wound dressings.

Dextran, is manufactured by the fermentation of sucrose

by Leuconostoc mesenteroides or related species of bacteria is

also being developed as a fibrous non-woven for speciality

end-uses such as wound dressings. Additional biopolymers, not

previously available on a large scale are now coming onto the

market thanks to biotechnology. One such example is hyaluronic

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acid a polydisaccharide of D-glucuronic acid and N-acetyl

glucosamine found in the connective tissue matrices of

vertebrates and is also present in the capsules of some

bacteria.

Two different biotechnological routes for the production

of cellulose are under investigation in various laboratories

throughout the world. Cellulose is produced as an

extracellular polysaccharide by a number of different bacteria

in the form of ribbon-like microfibrils. These can be used to

produce moulded materials of relatively high strength. Sony,

the Japanese electronics company has patented a way of making

hi-fi loudspeaker cones and diaphragms from bacterial

cellulose. An alternative route to cellulose, still at a very

early stage of development, concerns the in vitro cultivation

of plant cells. It has already been demonstrated that cotton

fibres can be produced in vitro by culturing cells of various

strains of Gossypium. The potential advantages of this route

include a more uniform product displaying particularly

desirable properties. Plant tissue culture can provide a

steady, all year supply of products without climatic or

geographic limitations free of contamination from pests.

Another group of biopolymers of particular interest to

biotechnologists are proteins because of the scope for

utilising the new genetic manipulation techniques. Thus genes

for animal and plant proteins (e.g. collagen, various silks)

can now be transferred into suitable microbial hosts and the

proteins produced by fermentation. The US army is keen to

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develop spider silk as a high performance fibre for use in

products such as bulletproof vests.

2. Enzymes Today, enzymes have become an integral part of the

textile processing. Though the use of enzymes in desizing was

established decades ago, only in recent years the applications

have widened with the introduction of new products. With the

increased awareness and regulation about the environment

concerns, the enzymes are the obvious choice. This is because

the enzymes are biodegradable, work under mild conditions and

save the precious energy. Enzymes, being biocatalyst and very

specific, are used in small quantities and have a direct

consequence of lesser packing material and lower

transportation impact. In an overall consideration, the

enzymes are the wonder products.

The preparation of certain textile fibres such as flax

and hemp by dew retting involves the action of pectolytic

enzymes from various microorganisms, which degrade pectin in

the middle lamella of these plant fibres. One enzyme that is

already being applied in textile processing for the removal of

hydrogen peroxide prior to dyeing is catalase.

There has been a dramatic increase in the use of enzymes

in detergents. Washing powders are referred to as ‘biological’

because they contain enzymes. Enzymes are now available that

can degrade a wide range of stains and their use allows milder

washing conditions at lower temperatures which both saves

energy and protects the fabric. Recently it was discovered

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that cellulase enzymes could replace the pumice stones used by

industry to produce 'stone-washed' denim garments. The stones

can damage the clothes, particularly the hems and waistbands,

and most manufacturers are now using the enzyme treatment.

Another novel application for cellulase enzymes is in

biopolishing, the removal of fuzz from the surface of

cellulosic fibres, which eliminates pilling making the fabrics

smoother and cleaner looking. A similar process using protease

enzymes has been developed for wool.

Enzyme Application Remarks

Amylase

Desizing of

woven cotton

and man-made

fabrics

Improving speed, economics and

consistency of the process, use of

thermostable enzyme, characterisation of

the process, are the developments in the

amylase applications.

Lipase DesizingTo remove triglyceride-based size

lubricants from fabrics.

Xylanas

e

Scouring and

bleaching

Pectins, waxes, colour, residual seed

coatings can be removed. These

substances, inhibit the natural

absorbency of the fibre and prevents

dyeing, printing or other finishing of

cotton yarns and fabrics. Earlier

scouring was done by caustic soda,

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removes desirable natural lubricants and

other materials, and causes serious

effluent disposal problem.

Catalas

e

To break down

residual

hydrogen

peroxide.

Reactive dyes are especially sensitive

to peroxides and currently require

extended rinsing and/or use of chemical

scavengers.

Pectina

seRetting of

flax

Rapid and controlled process is possible

with use of enzyme preparation and no

bacterial or fungal contamination occurs

like that in dew and water retting. Also

pre-treatment of flax with SO2 brings

about sufficient breakdown of woody

straw to speed-up enzyme action and

prevent bacterial and fungal

contamination.

Cellula

ses and

pectina

ses

Carbonization

Conventionally, vegetable matter in wool

is degraded by treatment with strong

acid and then subjected to mechanical

crushing. This can, in principle, be

replaced by selective enzyme degradation

of the impurities. Cellula

seBiostoning Uniform and quality finishing of fabric.

(100% use by Denim garment processors).

Earlier pumice stone was used to get

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characteristic abraded, faded

appearance.

Laccase Denim

finishing

This enzyme decolorises the indigo

dyestuff and enhances the apparent

abrasion effect with little or no impact

on cellulosic fibre strength.

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Cellula

se Biopolishing

To remove fine surface fuzz (protruding

fine fibres), surface pills (balls of

entangled fibres) and fibrils from

cotton and viscose fabrics. Treatment

gives cleaner, softer, smoother look and

feel.

Proteas

eWool

finishing

This is aimed at increased comfort

(reduced prickle, greater softness) as

well as improved surface appearance and

pilling performance.

Proteas

edegumming of

silk

To produce sand-washed effects on silk

garments. Treatment of silk-cellulosic

blends is claimed to produce some unique

effects. Proteases are also used to wash

down printing screens after use in order

to remove the proteinaceous gums, which

are used for thickening of printing

pastes.

Enzymes used in detergents

Enzyme Action

Protease Remove stains caused by proteins such as blood,grass, egg and human sweat

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Amylase Remove starch-based stains such as those made bypotatoes, pasta, rice and custard

Lipase Break down fats, oils and greases removing stainsbased on salad oils, butter, fat-based sauces andsoups, and certain cosmetics such as lipstick

Cellulase Brighten and soften the fabric, and releaseparticles of dirt trapped in the fibres

A. BIO-POLISHING:Commercial cellulases are mixtures of endoglucanses,

cellobio-hydrolases and Cellobiases. Endoglucanases attack

cellulose randomly and hydrolyze internal glycosidic bonds

whereas cellobiohydrolases remove terminal cellobiose residues

from both cellulase chain ends. Cellobiases hydrolyse small

cellobiose to glucose. This principle has allowed cellulase to

be used to modify the surface and properties of cellulosic

fibers and fabrics in order to an enzymatic removal of the

fuzz.

Biopolishing can be carried out any time during wet

processing, but it is most conveniently performed after

bleaching. The advantage of carrying out biopolishing at this

stage is that the fabric is clean, hydrophilic and more

accessible to the cellulases. If biopolishing is performed

after dyeing then there may be a risk of colour shade change,

any dyestuff may reduce the performance of enzyme so that a

higher concentration of enzyme would require.

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Recipe of Biopolishing Process:

Genecel HEBPL conc Liquid 0.3-0.8 %Time : 45-90 minutes.Temperature : 50 2 ºCpH : 4.5-5.5 (for acid stable cellulose)

ADVANTAGES OF ENZYMATIC BIO-POLISHING TREATMENT:

Enzymatic removal of the fuzz (bio-polishing) is

permanent and it not only keeps the fabric in good condition

after repeated washing but also enhances feel, colour,

drapeability, etc. and consequently the products fetch better

prices.

For bio-polishing of the cotton fabric, cellulase enzymes

are used which causes: (i) Prevention of the pills formation

(ii) Increased smoothness and softness (iii) Increased luster

and superior colour brightness (iv) Improved handle and

drapeability, and (v) Improved durable softness.

B. ENZYMATIC DESIZING:Alternative eco-friendly desizing agents are available in

the market in the form of enzymes. Complete removal of starch-

containing size without fiber damage is best obtained by using

enzymatic desizing agents. Formerly amylase derived from

pancreas or malt was used in desizing. Today liquid bacterial

amylase preparations dominate.

The enzymatic desizing process can be divided into three

stages:

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Impregnation: Enzyme solution is absorbed by the fabric. This

stage involves thorough wetting of fabric with enzyme

solution. During this stage, gelatinization of the size

(starch) is to the highest possible extent.

Incubation: The size is broken down by the enzyme. Long

incubation time allows a low enzyme concentration.

After-wash: The breakdown products from the size are

removed from the fabric. The desizing process is not finished

until the size breakdown products have been removed from the

fabric. This is best obtained by a subsequent detergent wash

(with NaOH) at the highest possible temperature.

ENZYMATIC DESIZING WITH AMYLASE:

The most popular method of removing starch from garments

is using amylase enzyme. Amylase breaks down the long starch

molecular chains into smaller fragments through

STARCH (insoluble) DEXTRIN (polysaccharides) MALTOSE

(disaccharides) GLUCOSE (monosaccharides - soluble) into

water-soluble or alkali soluble sugars. The degraded starches

are more soluble in alkali than in water. Hence an alkaline

wash after amylase based desizing is usually done.

Recipe for desizing with amylase:

Rexsize MHT 60 Powder 1.0-2.0 %Common salt 1.0-5.0 gms/lit

Kleenox PSF Liquid 0.5-1.0 gms/lit pH: 6.5-8.0 Temp. 60-65C

Time 30-90 mins

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It is important to follow the desizing with hot water

rinses. The cold-water rinse may re-solidify the unresolved

starch by enzymatic treatment and to redeposit it onto the

fabric surface.

C. ENZYMATIC SCOURING Scouring of textile material with enzymes is known as

Bio-Scouring. Bio-scouring is an enzymatic process, which can

be applied on any form cotton such as fiber, woven or knitted

fabrics and cotton blends. This process can be carried out on

various equipments such as jiggers, jets, pad batch, and pad-

steam range. The bio-scoured material can be used for

bleaching and dyeing. Suitable available enzymes for scouring

include protease, pectinase, hemicellulase and lipase. In

particular, pectinase can be used for scouring in the presence

of cellulase and lipase. The pretreatment with water is done

since wax and lipid compounds melt at temperature less than

100oC, exposure to water at 100oC should cause these compounds

to melt so as to disperse them into the pre-treatment water or

redistribute them over the fiber surface.

Recipe for exhaust method for bio scouring

Scourenz CBE New Powder 2.0 – 4.0 %H2O2 (50%) 3.0 %pH 10-11 Time 45 mins

Followed by hot wash and then cold wash.

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One bath enzymatic desizing / scouring / bleaching is

feasible when sufficient amyloglucosidase for glucose

production is present. Whiteness indices of the enzymatically

bleached goods are close to those fabrics bleached

conventionally with hydrogen peroxide. With lower costs and

less rinse water usage, the process presents an economically

interesting alternative for the textile preparation

industries.

D. PEROXIDE KILLERSAfter bleaching if the residual peroxide on the fabric is

not neutralised then it results in fabric tendering and

results in patchy dyeing. Conventional reducing agents used

for peroxide neutralisation are non-eco-friendly as they

increases the TDS of the effluent. Catalases on the other

hand catalyse the breakdown of hydrogen peroxide. Each

molecule of catalase being capable of processing around five

million molecules of hydrogen peroxide per second. Apart from

their specificity, high catalytic power and eco-friendliness

they does not interfere in dyeing and hence dyeing can be

continued in the same bath. Ultrox EPN 50 Liquid effectively

neutralises residual peroxide and hence avoids problems in

further processing

PEROXIDE NEUTRALISATION IN BATCH PROCESS

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At the end of peroxide bleaching, drain Rinse cold

Set the fresh bath at 45 – 55C and pH 6.0 – 7.0 with the Ultrox

EPN 50 Liquid 0.7–1.5 gms/lit Run the bath for 10-15 mins

Drain Adjust pH for required dye class and begin

dyeing in same bath

E. WOOL PROCESSINGTraditionally softening of coarser wool was carried out

using various chemicals such as silicones, dichloro

isocyanuric acid, tristearin and so on. now a days the

problem associated with the fuzz can be eliminated by removing

the fuzz using enzymatic treatment.

Enzymatic Softening of Wool

Load the material Add water Raise temperature

to 60ºC Adjust pH to 8.5 – 9.0

Add Zywet VPQ Liquid 0.5-1.0 gms/lit

Greasenz BSW Liquid 2.5 – 7.5 gms/lit

Run the machine for required time i.e. between 45 – 90 mins

Drain Rinse

Finish with

Zylon PLI Liquid 3 % o.w.f

At pH 5.0 – 5.5 and temp 50º C for 20 mins.

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It was observed the enzymatic treatment results in the

removal of the protruding fibers, which present on the surface

and gave a fuzzy appearance. During the enzymatic treatment,

the scales present on the surface were chemically modified and

due to this, a silky sheen is imparted to the surface of wool.

Thus, there ability to reflect light from their surface

increases, which improves luster of the wool after enzymatic

treatment. It results in the dissolution of the surface

fibers, which are stiff and coarser. Thus, smooth surface was

obtained after the enzymatic treatment and extra softness was

imparted. Since the enzyme dissolve the protruding surface

fibers completely the softening effect achieved is permanent.

F. DEGUMMING OF SILKThe raw silk thread consist about 70-80% fibroin and 20-

28 % of sericin. Sericin is chemically a non-filamentous

protein.

Set the bath with the following

Sodium Carbonate To adjust pH 8.5

Kleenon LXI Paste 2.0 – 3.0 gms/lit

Treat at 70C for 15 - 20 mins cool the bath to 600C

Add Silkenz DGM Liquid

5 – 10 gms/lit Run for 30 – 45 mins Drain two

hot washes at 900C for 15 mins each cold wash

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In silk sericin and fibroin both are proteins but due to

specificity of Silkenz DGM Liquid it only degrades sericin

without damaging fibroin, which is not possible otherwise with

conventional soda treatment. Hence, it improves degumming

efficiency, imparts soft feel and ensures maximum weight

reduction without affecting the fibre strength and hairiness.

G. POLYESTER PROCESSINGEnzymes in improving absorbency and wetting of polyester

fabrics:

The major draw back of alkaline hydrolysis includes

damage to fabric properties such as strength and caustic

discharge. Enzymes are protein molecules capable of catalyzing

specific chemical reaction of organic material. Hydrolyses are

capable of hydrolysing fatty acid or carboxylic ester, and in

principle, can hydrolyze the ester linkage in polyester.

Nowadays, a polyesterase enzyme with the polyester

article starting material under condition and for the time

suitable for the polyesterase to produce surface modification

and it disclosed a method for increasing the hydrophilicity of

a polyester to improve fabric characteristics such as stain

resistance, wettability, or a dyeability.

3. Textile Auxiliaries

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Textile auxiliaries such as dyes could be produced by

fermentation or from plants in the future. Many micro-

organisms produce pigments during their growth which are

substantive as indicated by the permanent staining that is

often associated with mildew growth on textiles and plastics.

Several of these microbial pigments have been shown to be

benzoquinone, naphthoquinone, anthraquinone, perinaphthenone

and benzofluoranthenequinone derivatives, resembling in some

instances the important group of vat dyes. Microorganisms

would therefore seem to offer great potential for the direct

production of novel textile dyes or dye intermediates by

controlled fermentation techniques replacing chemical

synthesis, which has inherent waste disposal problems e.g.

toxic heavy metal compounds.

Another biotechnological route for producing pigments

for use in the food, cosmetics, or textile industries is from

plant cell culture. One of the major success stories of plant

biotechnology so far has been the commercial production since

1983 in Japan of the red pigment shikonin, which has been

incorporated into a new range of cosmetics. Shikonin was

extracted from the roots of five year old plants of the

species Lithosperum erythrorhiz where it makes up about 1 to 2

percent of the dry weight of the roots. In tissue culture,

pigment yields of about 15 percent of the dry weight of the

root cells have been achieved.

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4. New Analytical Tools Research in biotechnology has already resulted in new

analytical methods for the textile industry. Work on molecular

biology has led to the development of species-specific DNA

probes for animal fibres. These probes can be used to detect

adulteration of high value speciality fibres such as cashmere

by much cheaper fibres e.g. wool and yak hair. Rapid methods

have been developed to assist in the early detection of

biodeterioration of textile and other materials. Studies show

that the presence of viable micro-organisms on textiles can be

assessed using the enzyme luciferase isolated from the firefly

(Photinus pyralis) which releases light (bioluminescence) in

combination with adenosine triphosphate produced by the micro-

organisms.

5. Waste Management

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Biotechnology can be used in new production processes

that are themselves less polluting than the traditional

processes and microbes or their enzymes are already being used

to degrade toxic wastes. Waste treatment is probably the

biggest industrial application of biotechnology. Specific

problems pertaining to the textile industry include colour

removal from dyehouse effluent, toxic heavy metal compounds

and pentachlorophenol used overseas as a rot-proofing

treatment of cotton fabrics. Currently much research is being

carried out to resolve these problems and biotechnology would

appear to offer the most effective solutions.

ConclusionToday, due to increasing awareness of environmental

concern, and important legislation on eco-toxicological

consideration issues such as health and safety during storage,

application and use, and safe disposal of chemical into

landfill and water or release in air during chemical

processing of textile is gaining importance.

So nowadays, with the increasingly important requirement

for textile manufacturers to reduce pollution in textile

production, the use of bio-enzymes in the chemical processing

of fibres and textiles is rapidly gaining wider recognition

because of their non-toxic and eco-friendly characteristics.

It is thus expected that in future, many of the

biotechnological processes would help in solving the

environmental problems posed by the textile industry.

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Further there is promising future for the reuse of

enzyme, which will not only decrease the processing cost

drastically but also bring about wide renovation in textile

wet processing.

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